Existing cooling systems generally have components including a compressor, a condenser, and an evaporator. In most systems, the compressor motor utilizes the majority of the energy as it starts up in order to provide the proper amount of cooling. However, repeatedly starting and running a compressor motor can be inefficient, because the start-up energy requirements of many compressor motors are high in comparison to the energy required to maintain the motor at a desired speed. In addition, the refrigeration system may not function at peak efficiency until the refrigerant pressure in the system increases to a certain target pressure because such systems use capillary tubing or other passive pressure reduction devices to move refrigerant to the evaporator. Because capillary tubing only allows a particular amount of refrigerant through at any given time, in some circumstances, the evaporator may be starved of refrigerant if the capillary piping cannot supply sufficient refrigerant to the evaporator. Conversely, during light loads, the capillary will provide too much refrigerant to the evaporator and may cause it to be flooded with refrigerant. Both evaporator starving and flooding reduce efficiency of the refrigeration system. Conventional modulating expansion valves are not employed as their poor response time and inaccurate superheat control only offers little advantage over the passive expansion devices, such as capillaries, orifice packs or porous plugs. In addition to the above energy efficiency and capacity deficiencies, flooding can result in liquid refrigerant entering the compressor, which can harm the compressor and reduce its life expectancy.